The plantar fascia is a ligament that runs along the bottom of the foot and connects the heel bone (calcaneus) to the base of the toes. It is a thick fibrous band of connective tissue that can stretch slightly. The plantar fascia supports the arch of the foot and facilitates foot movement.
Plantar fasciitis is characterized by pain and inflammation of the plantar fascia associated with microscopic tears at the origin or insertion of the plantar fascia on the heel bone. This microtearing on the cellular level leads to an inflammatory response and concomitant pain usually localized to the plantar medial heel region. Longstanding cases of plantar fasciitis often demonstrate more degenerative changes than inflammatory changes, in which case they are termed plantar fasciosis.
Plantar fasciitis usually affects one foot, although it can occur in both feet simultaneously. Plantar fasciitis pain is often most intense with the first steps of the day. In addition, it can be triggered by long periods of standing or getting up from a seated position. Another symptom associated with plantar fasciitis is decreased dorsiflexion of the ankle. Plantar fasciitis occurs in 2 million Americans a year and in 10% of the U.S. population over a lifetime. Activities such as long-distance running, ballet dancing and dance aerobics place a great deal of stress on the heel and plantar fascia. As a result, participants are more susceptible to plantar fasciitis. Occupations in which workers walk or stand for long periods, especially on hard surfaces, are associated with an increased incidence of plantar fascia injuries. Moreover, obesity is a risk factor.
The Achilles tendon is the large tendon in the back of the ankle that serves to attach the gastrocnemius (calf) and soleus muscles to the heel bone (calcaneus). It is the thickest and strongest tendon in the body. This tendon is approximately 15 cm. (6 in.) long, and runs from the middle of the calf to the heel.
Achilles tendonitis (also Achilles tendinopathy) is characterized by irritation and inflammation of the Achilles tendon. It is a common injury among recreational athletes and tends to be the result of overuse in less than ideal conditions. Achilles tendonosis is associated with chronic Achilles swelling and pain as a result of degenerative, microscopic tears within the tendon. Similar to plantar fasciitis/fasciosis, patients with Achilles tendonitis/tendonosis tend to experience pain after first walking in the morning and when standing after prolonged time in a seated position.